1000?

In 1000?, you want to get rid of all your cards in hand. On your turn, play a card higher than the one on the discard pile as long as it shares at least digit with that card. The 1000 card is an exception as it can be played over any other card and any card can be played over it.

Whenever you want, you can play a card face down and state that you've played a valid card for the turn. The next player can trust you and play, or they can reveal your card, with the player who bluffed or the player who mistakenly doubted the play drawing three cards as a penalty. (If you can't play and don't want to bluff, draw a card from the deck and add it to your hand to end your turn.)

Very similar (or identical?) to Trick 100